The field of the invention is silicon piezoresistive pressure sensors.
Prior art silicon piezoresistive sensors are made by etching thin (one mil or greater) diaphragms into the silicon because of the large piezoresistive effect in the silicon diaphragms.
The present invention has resistors fabricated in the silicon substrate adjacent a Si.sub.3 N.sub.4 diaphragm by ion implantation through the Si.sub.3 N.sub.4 layer and utilizes the piezoresistive shear in the silicon substrate where the Si.sub.3 N.sub.4 diaphragm is attached, so as to retain the desirable properties of single crystal silicon with non-silicon diaphragm material.